Document Type

Working Paper

Publication Date



Fertility declines are now underway in many developing countries, and the focus of the debate about future fertility trends is shifting from the early to the later phases of the transition. This study examines patterns and determinants of fertility in the developing world using UN estimates of the total fertility rates for 143 developing countries from 1950 to 2000. The main objective is to identify regularities in the past record that may provide clues to future trends. Three key findings emerge from this analysis. First, the pace of fertility decline decelerates as countries reach the later stages of the transition. In the decade immediately following the transition onset, fertility usually declines rapidly and without interruption; but once fertility drops below about four births per woman, additional reductions occur, on average, at a substantially slower pace. Second, it is highly unlikely that developing countries will converge on replacement fertility of 2.1 children per woman as is often assumed in population projections. Past transition patterns suggest that a significant number of countries will likely stall above 2.1 for periods of up to decades or will approach low fertility at a very slow pace. Third, the future course of fertility depends crucially on progress in human development and on family planning effort. The recent experience of developing countries with relatively high levels of development suggests that life expectancy near 75 years combined with literacy near 95 percent is needed on average to reach replacement. Many countries are still far from these levels of human development and have weak family planning programs, thus making further progress through the transition difficult.